Largest haul of extrasolar planets for Japan

The 44 confirmed planets and their approximate size class, orbits and surface temperatures. Credit: John Livingston

Forty-four planets in solar systems beyond our own have been discovered in one go, dwarfing the usual number of confirmations from extrasolar surveys, which is typically a dozen or less. The findings will improve existing models of solar systems, and may help researchers investigate exoplanet atmospheres. Novel techniques developed to validate the find could accelerate the confirmation of more extrasolar planet candidates.

An international team of astronomers pooled data from NASA's Kepler and the ESA's Gaia space telescopes, as well as ground-based telescopes in the U.S. With John Livingston, lead author of the study and a graduate student at the University of Tokyo, the team's combined resources led to the confirmed existence of these 44 exoplanets and described various details about them.

A portion of the findings yield some surprising characteristics: "For example, four of the planets orbit their host stars in less than 24 hours," says Livingston. "In other words, a year on each of those planets is shorter than a day here on Earth." These contribute to a small but growing list of "ultrashort-period" planets, suggesting that they could be more common than previously believed.

"It was also gratifying to verify so many small planets," continues Livingston. "Sixteen were in the same size class as Earth, one in particular turning out to be extremely small—about the size of Venus—which was a nice affirmation, as it's close to the limit of what is possible to detect."

The 44 confirmed planets and their approximate size class, orbits and surface temperatures. Credit: John Livingston

The source observations for this study were made by Kepler, which was repurposed after a fault in 2013 that prevented accurate control of the space telescope. "Two out of the four control reaction wheels failed, which meant Kepler couldn't perform its original mission to stare at one specific patch of the sky," explains Professor Motohide Tamura of the University of Tokyo. "This led to its contingent mission, K2—our observations came from campaign 10 of this mission. We're lucky Kepler continues to function as well as it does."

The planets observed by K2 are known as transiting planets because their orbits bring them in front of their host stars, slightly reducing their brightness. However, other astrophysical phenomena can cause similar signals, so follow-up observations and detailed statistical analyses were performed to confirm the planetary nature of these signals. As part of his doctoral work, Livingston traveled to Kitt Peak observatory in Arizona to obtain data from a speckle interferometer camera installed on a large telescope there. These observations, along with follow-up observations from a telescope in the state of Texas, were necessary to characterize the host stars and rule out false positives. The combination of detailed analyses of data from these ground-based telescopes, K2 and Gaia enabled the precise determination of the planets' sizes and temperatures. The team's findings include 27 additional candidates that are likely to be real planets, which will be the subject of future research.

Scientists hope to understand what kinds of planets might be out there, but can only draw valid conclusions if there are enough planets for robust statistical analysis. The addition of a large number of new planets, therefore, leads directly to a better theoretical understanding of solar system formation. The planets also provide good targets for detailed individual studies to yield measurements of planetary composition, interior structure and atmospheres—in particular, the 18 planets in several multi-planet systems. "The investigation of other solar systems can help us understand how planets and even our own solar system formed," says Livingston. "The study of other worlds has much to teach us about our own."

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6 comments

put politics and religion to destroy them all, all those are happy planets because the are no humans there

thanos is right

over population is a problemthe world is beautiful there is nothing wrong with the world the only problem is the bad humanspeople always wonder why we don't see any aliensI'm a human and I stay away from peopleI guess that will answer their questionif I'm an alien I will stay away too from the destructive an ignorant humansThere are some good humans but the number is very littlebeware of the beast man as he will kill his brother to posses his landplanet of the apeslol

You child, we live in hell on Earth, if man can make it a bit less of a hell so be it. Population is now flattening out, as the 3rd world gets more civilized. If you only get one good idea in a million, you get a 1000 good ideas with a billion. Bad humans? you dope.

civilized humans, do you see the news, threats of wars, missiles etc and you call that civilizedif at this point they haven't reach a high intellect then they never will or it will take them another million years, population flattening out, are you sure we live in the same dimension or in the same time linelast time I checked there was more babies being born than people dyingwe are over populated an that is a fact, but don't worry believe what ever you wantI really hope all natural resources run out soon so you get to see civilize humansI'm a realistic person and I don't believe in fairy talesthey put os here and they flew far away from us, so we never reach themI really wish I can be optimistic like you but you are expecting too much from your fellasat the end you will be disappointed and the funny thing is that you called me childhaha later man

everything that goes wrong is the poor devil fault, why can't you blame your godif you don't dare no problem but I do dareare you sure the fake god from the Bible is the real godread the Old Testament where the all knowing killed almost everybody and sent plaguesbut if he knew all that was going to happen why create something to then destroy itmaybe he is not all knowing, he works on mysterious ways, yes nice jokehow bout the devil is the good guy and god is the bad guywhere god wanted Adam and eve to be ignorant. so he can control them and the devil wanted them to be free and to open their eyes so they can see the truthbut he is evil because of that, this not hell this actually heavencheck out the anunnakies from an alternate creation storythe priest say the devil is bad and you believe himis not the devil who is the child molester is the priest that got god in his heart and the Holy Spiritgod is a murderer and Jesus committed suicidehow you like me now

It makes me wonder how our descendants will end up treating the native life of any earthlike planets they happen across. Will they be more enlightened than we are now and treat life kindly, or will they see the planets as theirs for the taking, native life be damned?

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